3 Lesson 3 Bacteria

Ex. 3.1 Words and word-combinations to the text

chlorophyll – хлорофилл

to magnify – увеличивать

sphere – шар

rod – палочка

spiral – спираль

ubiquitous – вездесущий, повсеместный

habitat – место расположения, естественная среда

fission – размножение путём деления клеток

to multiply – размножаться

dividing – деление

to thrive – буйно, пышно расти

germ – микроб

dot – точка

comma – запятая

string – верёвка, шнурок

chain – цепь

cluster – гроздь

benefit – извлекать пользу

intestine – кишечник

to digest – переваривать

yeast – дрожжи

mold – плесень

Ex. 3.2 Translate the following word-combination

green colouring matter –

compound microscope –

radioactive waste –

world's biomass –

quarter of a pound –

inviting ecological niche –

chief credit –

to be responcible –

diverse community –

complex carbohydrates –

organic compounds –

waste processing –

environmentally friendly –

relative ease –

Ex. 3.3 Read and translate the text

Bacteria

Bacteria are tiny one-celled plants, without green colouring matter /chlorophyll/, that can be seen only under a compound microscope that magnifies them from 600 to 1200 times. Typically a few micrometers in length, bacteria have a wide range of shapes, from spheres to rods and spirals. Bacteria are ubiquitous in every habitat on Earth, growing in soil, radioactive waste, seawater, and deep in the Earth's crust. There are approximately five nonillion (5x10³⁰) bacteria on Earth, forming much of the world's biomass.

At the moment you were born, all damp and wiggy; your body harbored no bacteria. But in hours they colonized this inviting ecological niche, arriving on the air, doctor's hands, in mother's milk. Today you carry about a quarter of a pound. Oldest of life–forms (for two billion years the only life on earth), bacteria are structurally the simplest, lacking the cell nucleus found in other microbes. Most reproduce by fission: they multiply by dividing. Bacteria thrive as the planet's most abundant, most varied, most versatile, and most useful organisms – and among its most deadly.

The discovery that bacteria cause disease was one of the greatest of all advances in medical science. Chief credit for the germ theory of disease goes to the French chemist, Louis Pasteur, and the German doctor, Robert Koch. Bacteria come in many different sizes but in three principal shapes: rod-or pencil-shaped bacteria, the bacilli, produce diseases like tuberculosis and leprosy; spherical or dot-shaped, the cocci; and spiral or comma-shaped, such as the corkscrew spirochete of syphilis or the cholera vibrio. The cocci come in pairs (diplococci), strings ar chains (streptococci), or clusters, like grapes (staphylococci). Typical diplococci are the gonococcus, cause of gonorrhea, and the pneumococcus, cause of pneumonia. Streptococci are responsible for “strep” infections, such as the sore throat that is often a forerunner of rheumatic fever. Staphylococci are often present in boils. We benefit from many bacteria living inside us. In the large intestine alone, a diverse community of a hundred trillion bacterial cells acts as a barrier against pathogens. These cells also produce nutrients that the intestinal wall absorbs, derived from food the small intestine cannot digest, mucous gel, secreted by goblet cells, and other bodily substances. Making up some 70 percent of the bacterial volume, Bacteroides and Eubacterium break down the complex carbohydrates from the whole grains, fruits, and vegetables. Other bacteria such as Acidaminococcus, Bifidobacterium, Butyrivibro, Coprococcus, Fusobacterium, Lactobacillus, Peptostreptococcus, and Ruminococcus, complete the breakdown of food. Bacteria, often Lactobacillus in combination with yeasts and molds, have been used for thousand of years in the preparation of fermented foods such as cheese, pickles, sauerkraut, vinegar, wine and yoghurt. The ability of bacteria to degrade a variety of organic compounds is remarkable and has been used in waste processing and bioremediation. Bacteria capable of digesting the hydrocarbons in petroleum are often used to clean up oil spills. Bacteria can also be used in the place of pesticides in the biological pest control. These pesticides are regarded as environmently friendly, with little or no effect on humans and wildlife. Because of their ability to grow and the relative ease with which they can be manipulated, bacteria are the workhorses for the fields of molecular biology, genetics and biochemistry.

Ex. 3.4 Decide if each statemrnt below is true or false according to the reading. If the statement is false, tell why

1. Bacteria are the most numerous microscopic microorganisms.

2. Your body harbored bacteria at the moment you were born.

3. Bacteria reproduce by fission.

4. All bacteria cause diseases.

5. The cocci come in pairs.

6. Many bacteria live inside us.

7. Bacterial cells can not act as a barrier against pathogens.

8. Bacteria are not able to digest the hydrocarbons in petroleum.

9. Some bacteria are our fermenters, converting sugars into bread, beer, sauerkraut, etc.

10. Bacteria are the workhorses of molecular biology, genetics, biochemistry.

Ex. 3.5 Read the text, translate it, give a little to it, make up a dialogue using given information

Bacteria were first observed by Antonie van Leenwenhoek in 1676, using a single-lens microscope of his own design. He called them “animalcules” and published his observations in a series of letters to the Royal Society. The name bacterium was introduced mach later, by Christian Gottfried Ehrenberg in 1828, and is derived from the Greek word, meaning “small staff”.

Louis Pasteur demonstrated in 1859 that the fermentation process is caused by the growth of microorganisms, and that this growth is not due to spontaneous generation. (Yeasts and molds, commonly associated with fermentation, are not bacteria, but rather fungi). Along with his contemporary, Robert Koch, Pasteur was an early advocate of the germ theory of disease. Robert Koch was a pioneer in medical microbiology and worked on cholera, anthrax and tuberculosis. In his research into tuberculosis, Koch finally proved the germ theory, for which he was awarded a Nobel Prize in 1905. In Koch’s postulates, he set out criteria to test if an organism is the cause of a disease; these postulates are still used today.

Ex. 3.6 Translate from Russian into English

1. Сотни тысяч видов микробов живут на земле.

2. Некоторые бактерии помогают делать фармацевтические препараты.

3. В течение двух миллиардов лет бактерии были единственной формой жизни на Земле.

4. Ни мы, ни наша планета не могли бы жить без микроорганизмов.

5. Бактерии - группа прокариотных (безъядерных) микроорганизмов, чаще всего одноклеточных.

6. Впервые бактерий увидел в оптический микроскоп и описал голландский натуралист Антони ван Левенгук в 1676 году.

7. Как и всех микроскопических существ, он назвал их «анималькули».

8. Название «бактерии» ввёл в употребление Христиан Эренберг в 1828.

9. Луи Пастер в 1850-е положил начало изучению физиологии и метаболизма бактерий, а также открыл их болезнетворные свойства.

10. К настоящему времени описано около десяти тысяч видов бактерий и предполагается, что их существует свыше миллиона.

Ex. 3.7 Answer the following questions

1. What are bacteria?

2. Describe the three principal shapes of bacteria.

3. Where can we find bacteria?

4. Do bacteria have the cell nucleus found in other microbes?

5. How do bacteria multiply?

6. Who founded the germ theory?

7. In what shapes do bacteria come?

8. What diseases can bacteria cause?

9. What are the benefits of bacteria?

10. What do you know about history of bacteriology?

Ex. 3.8 Retell the text “Bacteria”.